Comparative toxicities of alpha- and beta-N-oxalyl-L-alpha, beta-diaminopropionic acids to rat spinal cord

alpha- and beta-N-oxalyl-L-alpha, beta-diaminopropionic acids, isolated from Lathyrus sativus seed, which is implicated in the pathogenesis of human neurolathyrism, were injected into rat lumbar cerebrospinal fluid. The alpha-isomer was neither acutely nor chronically toxic, whereas the beta-isomer was both an acute and a chronic neurotoxin in this test system. These results are relevant to the aetiology of neurolathyrism and suggest that the conversion of the beta- to the alpha-isomer that occurs during boiling of the seed prior to human consumption reduces the neurotoxicity of the seed.